Shifting eccentric



(No Mode1,)

J. GRANT.

SHIPTING BGGENTRIG. No. 363,629. Patented May 24, 188'?.

Y I' 'Gl Lei- /N VEN TOR N. PETERS, Pholo-Lithoghyhef. Washinglun. D C.

`UNrTnD STATES PATENT OFFICE.

JOHN GRANT, OF CHICAGO, ILLINOIS.

SHIFTING ECCENTRIC.

SPECIFICATION forming part of Letters Patent No.363,629, dated May24, 1887.

Application filed October 2G, 1586. Serial 1531.211223.

To all whom, it may concern:

Be it known that I, J oHN GRANT,of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Shifting Eccentrics; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification. Y

This invention relates to that class of shifting eccentrics for steam-engines in which the eccentric engaged with the eccentricArod is mounted upon a second eccentric Xed to the engineshaft, so that by turning the outer eccentric upon the inner one the throw of the valve may be changed or the engine reversed. The invention relates more particularly to an improved actuating device for moving or turning the outer eccentric with relation to the inner one in a device of the character above mentioned, as will hereinafter fully appear.

The invention consists in the matters hereinafter described, and pointed out in the appended claims.

In the accompanying drawings, illustrating my invention, Figure l is a sectional elevation taken upon line x a: of Fig. 2, showing in side or face View the two eecentrics in a device embodying my invention. Fig. 2 is a section taken longitudinally through the shaft-axis upon line a :c of Fig. l. Fig. 3 is a side elevation of the main or outer eccentric detached from other parts of the device. similar view of the inner eccentric, or the one attached to the shaft. Fig. 5 is a detail view of a plate shown in Fig. 2 as attached to the inner eccentric, for holding the latter in engagement with the main or outer eccentric. Fig. 6 is a sectional view taken upon line y y of Fig. 2, illustrating the shifting device therein shown. Fig. 7 is a detail sectional View illustrating another form of shifting device.

As illustrated in the said drawings, A is the engine-shaft; B, the small 0r inner eccentric, attached tosaid sha-ft; C, the outer eccentric, mounted to rotate upon the inner eccentric, B; and D, the eccentric-rod, provided with the usual straps, D' D', engaging the peripheral surface of the outer eccentric, C. The said eccentric C is provided near its outer edge, at

Fig. 4. is a (No model.)

F', which extends outwardly at one side of the eccentrics parallel with the main shaft. The said screw or spiral shaft F is engaged with a nut, G, mounted on a slide, G', which slide is supported and constructed to slide longitudinally upon the main shaft A. The said spiral or screw stem is provided with a very quick thread, so that when the nut G is moved lougitudinallywith reference thereto the said stem and the pinion F will be rotated, `and thereby cause the desired movement of the outer eccentric.

In one convenient form of the slide G' and shifting devices therefor (illustrated in Figs. 1, 2, and 6) the said slide is provided with a sleeve, g, which is splined upon the shaft A, and with a circular ring or disk, g', attached to the said sleeve and supporting the nut, the outer surface or periphery of the said ring. or disk being arranged to extend around the shaft and the spiral ring F' eoncentricall y with the shaft. The nut Gis in this ease iliade integral with the said plate or .disk g'. The disk y' is provided withV a peripheral rib, gt', engaged by plates 7L, pivotally connected with the forks H' of a shifting-lever II.

In another form of the shifting device (shown in Fig. 7) a sliding sleeve, g, is splined upon the shaft A, said sleeve being provided with an arm, g3, in the outer end of which the nut G is formed. The sleeve g is actuated in this case by means of a shifting-lever, H, having a bent U-shapcd arm, H2, which is pivoted at its outer end to a ring, g", running in a groove, g5, in the sleeve g, the bent arm H? of the shift ing-lever being so shaped as to allow the passage ofthe stem F' in all positions ofthe said sleeve. v

In a convenient construction of the inner cam, B, and the bearings b for the pinion F, herein shown, the said eccentric is keyed t0 the shaft, and is provided at one side With a flange, b2, extending outwardly at one side of the eccentric to form the bearing I), the said iiange b2 forming the side bearing for the eccentric O at one side of the latter. The said eccentric Gis held upon the eccentric B by means of a removable plate, B, secured against the face of the eccentric B by screws b3 or otherwise, said plate B being constructed to overlap the eccentric C at its edges, and being eX- tended at one side to form the second bearing, b', for the pinion F. The said eccentric B is preferably provided with VYa flange, Zf, surrounding the shaft at its side adjacent to the plate B, and the central aperture of the said plate is made of proper size to iit around the. .iiange b4, so asto hold the said flange in po# sition without relying solely upon the attaching-screws for this purpose.

As a convenient means of constructing the stern F, the latter preferably consists of a bar rectangular in crossscction and bent or twisted in spiral form, the nut G being provided with a rectangular aperture fitting the bar, as clearly shown in Fig. 3.

In a device comprising a stem, F, made with a continuous spiral, such as shown in Fig. 2, any movement of the outer eccentric, C, in a direction to turn it about the inner eccentric will obviously tend to turn the pinion F and shaft F', and thereby tend to move the' nut G, and in a device thus made, unless the stem be qui'telongandthcpitch correspondinglyquick, a locking device for holding theshifting-lever positivelyin place may be desirable. The device shown is more particularly intended as a reversing device, the parts being so arranged for this purpose that when the pinion F is at the middle of the rack C the eccentric-rod will have no movement, and When the pinion is at opposite ends of the rack the engine-shaft will be caused to turn in opposite directions. In a device thus constructed the'stem F may be desirably provided with a straight part, j", atiis middle and other straight parts, ffz, at its ends, as indicated in Fig. 7, so that when the nut G is placed at either of the points mentioned the said stem will be positively locked from rotation. Vhen the stein is provided with straight partsfffg, as above described, any locking devices for holding the eccentric in position at the middle or at either end of its employedin connection With that class ofen-V gine-governors in which the valves are controlled by governing devices operating to shift the eccentric upon the shaft.

I claim as my inventionl. The combination, with an engine shaft, anv eccentric ixed on the shaft, and an outer eccentric provided with a rack, of a pinion mounted upon the eccentric which is attached to the shaft, and provided with a spiral stein, and a sliding nut engaging said stem, substantially as described. Y*

2. The combination, with an engineshaft, an eccentric fixed upon the shaft, and an outer eccentric provided with a rack, of a pinion mounted upon the eccentric which is attached tothe shaft, and provided with a spiral stem, said spiral stem being provided with one or more straight parts or sections, substantially as described.

3. The combination, withan engineshaft, an eccentric fixed upon the shaft, and an outer eccentric provided with a rack, of a pinion mounted upon the eccentric which is attached to the shaft, and provided with a spiral stem, anut engaging the spiral stem, a slide encircling the shaft and stein and supporting the nut, and a forked shifting-lever engaging the slide, substantially as described.

In testimony that I claim the foregoing as my invention I afiix my signature in presence of two Witnesses.

JOHN GRANT.

VitneSSes:

G. CLARENCE POOLE, CnAnLns T. BORING. 

